title: The intestinal lactase polymorphism in Papua New Guinea.
abstract: Discovery of small numbers of people with the gene for persistence of intestinal lactase into adult life (PL) in several parts of Papua New Guinea (PNG) suggests that sporadic mutation as well as diffusion could account for at least part of its present distribution. The existing hypotheses attempting to account for at least part of its present distribution. The existing hypotheses attempting to account for the distribution of the gene have been applied to the available evidence in PNG populations. The water absorption and linkage disequilibrium hypotheses are possible explanations for selection of the trait; the culture historical and calcium absorption hypotheses seem unlikely, however, to explain the observed frequencies. It seems possible that more intensive study of the properties of the enzyme might reveal a connection with processes other than lactose hydrolysis.
mesh_terms: D000483:Alleles; D005696:Galactosidases / Q000235:genetics*; D005787:Gene Frequency; D006801:Humans; D007421:Intestine, Small / Q000648:ultrastructure; D008871:Microvilli / Q000201:enzymology; D008962:Models, Theoretical; D009154:Mutation; D009512:New Guinea; D011110:Polymorphism, Genetic; D001616:beta-Galactosidase / Q000235:genetics* / Q000378:metabolism
chemical_list: D005696:Galactosidases; D001616:beta-Galactosidase